The present invention relates generally to weld assemblies for forming conductor to conductor welded connections and more particularly to single use weld molds for exothermically creating more easier and efficient welded electrical connections.
Exothermic weld assemblies are useful to connect two or more conductors, such as electrical wires to grounding rods or reinforcing rods and the like. Exothermic welds have long been recognized as having an excellent electrical quality connection between two or more conductors. Exothermic welds provide low resistance, high ampacity and long-lasting, reliable grounding connections.
Conventional exothermic weld assemblies typically have a crucible in a top section in fluid communication with a mold section therebelow by a tap hole extending from the bottom of the crucible. The crucible includes a chamber for holding a quantity of exothermic material. The mold section has a weld chamber in which the ends of the conductors to be welded together are inserted therein. The crucible and mold may be designed as a single unit or two individual units and each unit may be disposable or reusable.
The exothermic material in the crucible is ignited to produce a chemical reaction that is completed typically in seconds and produces a molten metal. The liquid metal flows from this crucible section into the weld chamber of the mold section where it envelops the ends of the conductors causing them to melt and thereby weld together.
The ends of the conductors to be welded are inserted into the weld chamber via guide holes, which allow the weld chamber to communicate with the outside of the weld assembly. Typically, these guide holes are formed by drilling a hole through the mold of the weld assembly into the weld chamber. Multiple guide holes may be drilled depending upon the application and the number of conductors to be joined. The target conductors that are to be welded together are then inserted into the weld chamber via the guide holes. Examples of such exothermic weld molds are disclosed U.S. Pat. No. 3,020,608 (""608 patent) and U.S. Pat. No. 5,715,886 (""886 patent), which are incorporated herein by reference.
Conventional weld molds are disposable, single use units that are generally circular shaped structures and, as such, have a curved outer surface. One of the problems with conventional weld mold assemblies is that it is difficult to drill the requisite holes leading into the weld chamber on the circular surface of the weld assembly as shown in the ""886 patent. Additionally, it is difficult to accurately and efficiently drill multiple holes in a weld assembly with a curved surface. Thus, conventional exothermic weld assemblies are less than satisfactory.
Accordingly, it would be desirable to provide an exothermic weld assembly with a flat outer surface that allows for easy, accurate and highly efficient drilling of holes.
An exothermic weld mold assembly for forming conductor to conductor welded connections, having preferably an octagonal body which allows for flat surfaces to be drilled perpendicular, therefore allowing for more easier and efficient production of wire holes. In addition, the flat surfaces provide for easier and more effective positioning within fixtures used for secondary operations.
In accordance with one embodiment of the present invention, there is provided an exothermic disposable weld mold assembly having a crucible section including a reaction chamber. A mold section having a weld chamber in communication with the reaction chamber. The mold section includes a plurality of flat exterior surfaces, where at least two of such surfaces each have a hole extending therethrough in communication with the weld chamber. In this assembly, both the crucible section and the mold section are designed as a single unit, permanently attached and disposed after use.
In accordance with another embodiment of the present invention, there is provided an exothermic weld mold assembly having a reusable crucible section including a reaction chamber. The crucible section has an open top for receiving an exothermic material in the reaction chamber. Also included is a disposable mold having a plurality of flat exterior surfaces, a top portion and a bottom portion. A weld chamber is located between the top and the bottom portion of the mold. The weld chamber has an opening to the top portion of the mold which is in communication with the reaction chamber. A hole extends through at least two of the flat exterior surfaces and communicates with the weld chamber. Additionally, a conductor is disposed in at least two holes with ends of the conductors projecting into the weld chamber. In this assembly, both the crucible section and the mold sections are designed as two individual units, temporarily attached, where the crucible section can be reused while the mold section is disposed after use.